The present invention relates to new organic compounds (e.g., ligands), their metal complexes and compositions using those compounds; the invention also relates to the field of catalysis. In particular, this invention relates to new compounds which when combined with suitable metals or metal precursor compounds provide useful catalysts for various bond-forming reactions, including polymerization, oligomerization or small molecule catalysis. This invention also relates to a method of making the ligands of this invention where the synthesis involves an aryl amination reaction. The invention also relates to combinatorial chemistry in that combinatorial techniques were used in connection with creating the ligands and testing compositions containing the ligands.
Ancillary (or spectator) ligand-metal coordination complexes (e.g., organometallic complexes) and compositions are useful as catalysts, additives, stoichiometric reagents, monomers, solid state precursors, therapeutic reagents and drugs. Ancillary ligand-metal coordination complexes of this type can be prepared by combining an ancillary ligand with a suitable metal compound or metal precursor in a suitable solvent at a suitable temperature. The ancillary ligand contains functional groups that bind to the metal center(s), remain associated with the metal center(s), and therefore provide an opportunity to modify the steric, electronic and chemical properties of the active metal center(s) of the complex.
Certain known ancillary ligand-metal complexes and compositions are catalysts for reactions such as oxidation, reduction, hydrogenation, hydrosilylation, hydrocyanation, hydroformylation, polymerization, carbonylation, isomerization, metathesis, carbon-hydrogen activation, carbon-halogen activation, cross-coupling, Friedel-Crafts acylation and alkylation, hydration, dimerization, trimerization, oligomerization, Diels-Alder reactions and other transformations.
One example of the use of these types of ancillary ligand-metal complexes and compositions is in the field of single site polymerization or oligomerization catalysis. In connection with single site catalysis, the ancillary ligand offers opportunities to modify the electronic and/or steric environment surrounding an active metal center. This allows the ancillary ligand to create possibly different polymers or oligomers. It also allows for higher reactivity under changing process conditions.
Moreover, it is always a desire to discover new ancillary ligands, which upon coordination to a metal center or addition of a metal compound or precursor will catalyze or assist in catalysis of reactions differently from known ligand systems. This invention provides new ancillary ligands that may be used for coordination to a metal center or included in a composition with a metal or metal precursor compound. Upon coordination to the metal center or inclusion in the composition, such ligands influence the electronic and steric environment of the resulting coordination complex and may catalyze reactions differently, including more efficiently and selectively than known systems.
In one aspect, the invention disclosed herein is a new ligand, which can be characterized by the general formula: 
wherein each
R1, R2 and R3 is independently selected from the group consisting of hydrogen, alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, heteroalkyl, heterocycloalkyl, substituted heterocycloalkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, alkoxy, aryloxy, silyl, boryl, phosphino, amino, thio, seleno, and combinations thereof; optionally, R1 and R2 are joined together in a ring structure;
Q1 and Q2 are, independently, selected from the group consisting of hydrogen, alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, heterocycloalkyl, substituted heterocycloalkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, alkoxy, aryloxy, silyl, boryl, phosphino, amino, thio, seleno, and combinations thereof; optionally, Q1 and Q2 are joined together in a ring structure;
X is selected from the group consisting of O, P, S, anti N atoms; and a is 1 or 2, depending on X and its oxidation state.
The ligands can be included in a composition including a suitable metal or metal precursor compound, where the composition has catalytic properties. Also, the ligands can be coordinated with a metal precursor to form metal-ligand complexes, which may be catalysts. The metal-ligand complexes of this invention may be characterized by one of the following the general formulas: 
wherein R1, R2, R3, Q1, Q2, and X are as defined above. In addition, M is a transition metal selected from the group consisting of Sc, Y and Groups 4-12 of the Periodic Table of Elements; L is independently each occurrence, a neutral and/or charged ligand; and n is a number 0, 1, 2, 3, 4, or 5, depending on M. If X is nitrogen, a is either 1 or 2 depending on the type of bonding to the metal M. In these formulas, if X is oxygen, then a is either 0 or 1, depending on the type of bonding to the metal M. If X is phosphorus, a is either 1 or 2 depending on the type of bonding to the metal M and the oxidation state of the phosphorus. Similarly, if X is sulfur, a is 0 or 1 depending on the type of bonding to the metal M and the oxidation state of the sulfur.
These transition metal-ligand complexes or compositions catalyze reactions involving activation of and/or formation of Hxe2x80x94Si, Hxe2x80x94H, Hxe2x80x94N, Hxe2x80x94O, Hxe2x80x94P, Hxe2x80x94S, Cxe2x80x94H, Cxe2x80x94C, Cxe2x95x90C, Cxe2x89xa1C, C-halogen, Cxe2x80x94N, Cxe2x80x94O, Cxe2x80x94S, Cxe2x80x94P, and Cxe2x80x94Si bonds. Specifically, such reactions include carbonylation, hydroformylation, hydroxycarbonylation, hydrocarbonylation, hydroesterification, hydrogenation, transfer hydrogenation, hydrosilylation, hydroboration, hydroamination, epoxidation, aziridination, reductive amination, Cxe2x80x94H activation, insertion, Cxe2x80x94H activation-insertion, Cxe2x80x94H activation-substitution, C-halogen activation, C-halogen activation-substitution, C-halogen activation-insertion, cyclopropanation, alkene metathesis, alkyne metathesis, polymerization, alkene oligomerization, alkene polymerization, alkyne oligomerization, alkyne polymerization, co-polymerization, CO-alkene co-oligomerization, CO-alkene co-polymerization, CO-alkyne co-oligomerization and CO-alkyne co-polymerization.
Further aspects of this invention will be evident to those of skill in the art upon review of this specification.
The invention disclosed herein is a new ligand that may be combined with metals or metal precursor compounds to form coordination complexes or compositions of matter, which are useful as catalysts for chemical reactions.
As used herein, the phrase xe2x80x9ccharacterized by the formulaxe2x80x9d is not intended to be limiting and is used in the same way that xe2x80x9ccomprisingxe2x80x9d is commonly used. The term xe2x80x9cindependently selectedxe2x80x9d is used herein to indicate that the R groups, e.g., R1, R2, R3, R4, and R5 can be identical or different (e.g. R1, R2, R3, R4, and R5 may all be substituted alkyls or R1 and R2 may be a substituted alkyl and R3 may be an aryl, etc.). A named R group will generally have the structure that is recognized in the art as corresponding to R groups having that name. For the purposes of illustration, representative R groups as enumerated above are defined herein. These definitions are intended to supplement and illustrate, not preclude, the definitions known to those of skill in the art.
The term xe2x80x9calkylxe2x80x9d is used herein to refer to a branched or unbranched, saturated or unsaturated acyclic hydrocarbon radical. Suitable alkyl radicals include, for example, methyl, ethyl, n-propyl, i-propyl, 2-propenyl (or allyl), vinyl, n-butyl, t-butyl, i-butyl (or 2-methylpropyl), etc. In particular embodiments, alkyls have between 1 and 200 carbon atoms, between 1 and 50 carbon atoms or between 1 and 20 carbon atoms.
xe2x80x9cSubstituted alkylxe2x80x9d refers to an alkyl as just described in which one or more hydrogen atom to any carbon of the alkyl is replaced by another group such as a halogen, aryl, substituted aryl, cycloalkyl, substituted cycloalkyl, and combinations thereof. Suitable substituted alkyls include, for example, benzyl, trifluoromethyl and the like.
The term xe2x80x9cheteroalkylxe2x80x9d refers to an alkyl as described above in which one or more carbon atoms of the alkyl is replaced by a heteroatom selected from the group consisting of N, O, P, B, S, Si, Se and Ge. The bond between the carbon atom and the heteroatom may be saturated or unsaturated. Thus, an alkyl substituted with a heterocycloalkyl, substituted heterocycloalkyl, heteroaryl, substituted heteroaryl, alkoxy, aryloxy, boryl, phosphino, amino, silyl, thio, or seleno is within the scope of the term heteroalkyl. Suitable heteroalkyls include cyano, benzoyl, 2-pyridyl, 2-furyl and the like.
The term xe2x80x9ccycloalkylxe2x80x9d is used herein to refer to a saturated or unsaturated cyclic non-aromatic hydrocarbon radical having a single ring or multiple condensed rings. Suitable cycloalkyl radicals include, for example, cyclopentyl, cyclohexyl, cyclooctenyl, bicyclooctyl, etc. In particular embodiments, cycloalkyls have between 3 and 200 carbon atoms, between 3 and 50 carbon atoms or between 3 and 20 carbon atoms.
xe2x80x9cSubstituted cycloalkylxe2x80x9d refers to cycloalkyl as just described including in which one or more hydrogen atom to any carbon of the cycloalkyl is replaced by another group such as a halogen, alkyl, substituted alkyl, aryl, substituted aryl, cycloalkyl, substituted cycloalkyl, heterocycloalkyl, substituted heterocycloalkyl, heteroaryl, substituted heteroaryl, alkoxy, aryloxy, boryl, phosphino, amino, silyl, thio, seleno and combinations thereof. Suitable substituted cycloalkyl radicals include, for example, 4-dimethylaminocyclohexyl, 4,5-dibromocyclohept4-enyl, and the like.
The term xe2x80x9cheterocycloalkylxe2x80x9d is used herein to refer to a cycloalkyl radical as described, but in which one or more or all carbon atoms of the saturated or unsaturated cyclic radical are replaced by a heteroatom such as nitrogen, phosphorous, oxygen, sulfur, silicon, germanium, selenium, or boron. Suitable heterocycloalkyls include, for example, piperazinyl, morpholinyl, tetrahydropyranyl, tetrahydrofuranyl, piperidinyl, pyrrolidinyl, oxazolinyl, and the like.
xe2x80x9cSubstituted heterocycloalkylxe2x80x9d refers to heterocycloalkyl as just described including in which one or more hydrogen atom to any atom of the heterocycloalkyl is replaced by another group such as a halogen, alkyl, substituted alkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, alkoxy, aryloxy, boryl, phosphino, amino, silyl, thio, seleno and combinations thereof. Suitable substituted heterocycloalkyl radicals include, for example, N-methylpiperazinyl, 3-dimethylaminomorpholine, and the like.
The term xe2x80x9carylxe2x80x9d is used herein to refer to an aromatic substituent which may be a single aromatic ring or multiple aromatic rings which are fused together, linked covalently, or linked to a common group such as a methylene or ethylene moiety. The common linking group may also be a carbonyl as in benzophenone or oxygen as in diphenylether or nitrogen in diphenylamine. The aromatic ring(s) may include phenyl, naphthyl, biphenyl, diphenylether, diphenylamine and benzophenone among others. In particular embodiments, aryls have between 1 and 200 carbon atoms, between 1 and 50 carbon atoms or between 1 and 20 carbon atoms.
xe2x80x9cSubstituted arylxe2x80x9d refers to aryl as just described in which one or more hydrogen atom to any carbon is replaced by one or more functional groups such as alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, heterocycloalkyl, substituted heterocycloalkyl, halogen, alkylhalos (e.g., CF3), hydroxy, amino, phosphido, alkoxy, amino, thio and both saturated and unsaturated cyclic hydrocarbons which are fused to the aromatic ring(s), linked covalently or linked to a common group such as a methylene or ethylene moiety. The linking group may also be a carbonyl such as in cyclohexyl phenyl ketone.
The term xe2x80x9cheteroarylxe2x80x9d as used herein refers to aromatic rings in which one or more carbon atoms of the aromatic ring(s) are replaced by a heteroatom(s) such as nitrogen, oxygen, boron, selenium, phosphorus, silicon or sulfur. Heteroaryl refers to structures that may be a single aromatic ring, multiple aromatic ring(s), or one or more aromatic rings coupled to one or more nonaromatic ring(s). In structures having multiple rings, the rings can be fused together, linked covalently, or linked to a common group such as a methylene or ethylene moiety. The common linking group may also be a carbonyl as in phenyl pyridyl ketone. As used herein, rings such as thiophene, pyridine, isoxazole, phthalimide, pyrazole, indole, furan, etc. or benzo-fused analogues of these rings are defined by the term xe2x80x9cheteroaryl.xe2x80x9d
xe2x80x9cSubstituted heteroarylxe2x80x9d refers to heteroaryl as just described including in which one or more hydrogen atoms to any atom of the heteroaryl moiety is replaced by another group such as a halogen, alkyl, substituted alkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, alkoxy, aryloxy, boryl, phosphino, amino, silyl, thio, seleno and combinations thereof. Suitable substituted heteroaryl radicals include, for example, 4-N,N-dimethylaminopyridine.
The term xe2x80x9calkoxyxe2x80x9d is used herein to refer to the xe2x80x94OZ1 radical, where Z1 is selected from the group consisting of alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, heterocylcoalkyl, substituted heterocycloalkyl, silyl groups and combinations thereof as described herein. Suitable alkoxy radicals include, for example, methoxy, ethoxy, benzyloxy, t-butoxy, etc. A related term is xe2x80x9caryloxyxe2x80x9d where Z1 is selected from the group consisting of aryl, substituted aryl, heteroaryl, substituted heteroaryl, and combinations thereof. Examples of suitable aryloxy radicals include phenoxy, substituted phenoxy, 2-pyridinoxy, 8-quinalinoxy and the like.
As used herein the term xe2x80x9csilylxe2x80x9d refers to the xe2x80x94SiZ1Z2Z3 radical, where each of Z1, Z2, and Z3 is independently selected from the group consisting of alkyl, substituted alkyl, cycloalkyl, heterocycloalkyl, heterocyclic, aryl, substituted aryl, heteroaryl, substituted heteroaryl, alkoxy, aryloxy, amino, silyl and combinations thereof.
As used herein the term xe2x80x9cborylxe2x80x9d refers to the xe2x80x94BZ1Z2 group, where each of Z1 and Z2 is independently selected from the group consisting of alkyl, substituted alkyl, cycloalkyl, heterocycloalkyl, heterocyclic, aryl, substituted aryl, heteroaryl, substituted heteroaryl, alkoxy, aryloxy, amino, silyl and combinations thereof.
As used herein, the term xe2x80x9cphosphinoxe2x80x9d refers to the group xe2x80x94PZ1Z2, where each of Z1 and Z2 is independently selected from the group consisting of hydrogen, substituted or unsubstituted alkyl, cycloalkyl, heterocycloalkyl, heterocyclic, aryl, heteroaryl, silyl, alkoxy, aryloxy, amino and combinations thereof.
The term xe2x80x9caminoxe2x80x9d is used herein to refer to the group xe2x80x94NZ1Z2, where each of Z1 and Z2 is independently selected from the group consisting of hydrogen; alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, heterocycloalkyl, substituted heterocycloalkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, alkoxy, aryloxy, silyl and combinations thereof.
The term xe2x80x9cthioxe2x80x9d is used herein to refer to the group xe2x80x94SZ1, where Z1 is selected from the group consisting of hydrogen; alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, heterocycloalkyl, substituted heterocycloalkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, alkoxy, aryloxy, silyl and combinations thereof.
The term xe2x80x9cselenoxe2x80x9d is used herein to refer to the group xe2x80x94SeZ1, where Z1 is selected from the group consisting of hydrogen; alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, heterocycloalkyl, substituted heterocycloalkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, alkoxy, aryloxy, silyl and combinations thereof.
The term xe2x80x9csaturatedxe2x80x9d refers to lack of double and triple bonds between atoms of a radical group such as ethyl, cyclohexyl, pyrrolidinyl, and the like.
The term xe2x80x9cunsaturatedxe2x80x9d refers to the presence one or more double and triple bonds between atoms of a radical group such as vinyl, acetylenyl, oxazolinyl, cyclohexenyl, acetyl and the like.
In one aspect, the ligands of this invention may be characterized by the formula: 
wherein each R1, R2 and R3 is independently selected from the group consisting of hydrogen, alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, heteroalkyl, heterocycloalkyl, substituted heterocycloalkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, alkoxy, aryloxy, silyl, boryl, phosphino, amino, thio, seleno, and combinations thereof; optionally, R1 and R2 are joined together in a ring structure;
Q1 and Q2 are, independently, selected from the group consisting of hydrogen, alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, heterocycloalkyl, substituted heterocycloalkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, alkoxy, aryloxy, silyl, boryl, phosphino, amino, thio, seleno, and combinations thereof; optionally, Q1 and Q2 are joined together in a ring structure; and
X is selected from the group consisting of N, P, S and O atoms; and a is 1 or 2, depending on X.
In more specific embodiments, R1 and R2 are independently selected from a group consisting of hydrogen, alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, heterocycloalkyl, substituted heterocycloalkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, silyl, boryl and phosphino. Specific examples of R1 and R2 are methyl, ethyl, propyl, butyl, cyclohexyl, cyclopropyl, cycloheptyl, t-butyl, phenyl, 2,4,6-trimethylphenyl, 2,4,6-triisopropylphenyl, 2,6-dimethylphenyl, 2,6-diisopropylphenyl, biphenyl, naphthyl, benzyl, pyridyl, furyl, quinolyl, morpholinyl, trimethylsilyl, dimethyl-t-butylsilyl, triphenylsilyl, triethoxysilyl, dimethylboryl, diphenylboryl, diphenoxyboryl, 1,2-dioxyphenylboryl, 2,2xe2x80x2-biphenoxyboryl, 2,2xe2x80x2-dinaphthoxyboryl, diphenylphosphino, dibutylphosphino, dimethylphosphino, dicyclohexylphosphino, dicyclopentylphosphino and methylphenylphosphino. In those embodiments where R1 and R2 are joined together in a ring structure, the ring (including R1, R2, and N) has from 3 to 15 non-hydrogen atoms preferably between 5 and 10 non-hydrogen atoms, more preferably between 5 and 6 non-hydrogen atoms, as part of the backbone of the ring. Specific examples of R1 and R2 together are ethylene (giving a 3-membered ring), butylene (giving a 5-membered ring), bicyclooctyl, bicyclohexyl, 2,2xe2x80x2-biphenyl (giving a dibenzo fused 5-membered ring), 2,2xe2x80x2-binaphthyl (giving a dinaphtho fused 5-membered ring) and the like.
In one preferred embodiment, R1 is a substituted or unsubstitued phenyl. In the case of the substituted phenyl, there are from 1-5 substituents on the phenyl ring, with each of the substituents independently selected from the group consisting of halide, alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, heteroalkyl, heterocycloalkyl, substituted heterocycloalkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, alkoxy, aryloxy, silyl, boryl, phosphino, amino, thio, seleno, and combinations thereof. Even more preferably, there are 1, 2 or 3 substituents on the substituted phenyl and the substituents are selected from the group consisting of chloro, fluoro, iodo, bromo, methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclooctyl, phenyl, naphthyl, benzyl, trimethylsilyl and isomers thereof, where applicable. Here and throughout, xe2x80x9cwhere applicablexe2x80x9d is intended to mean that for those compounds in the list that have isomers, the isomers are included without having to list each one, which is a form over substance issue. For example, isopropyl, n-butyl, s-butyl, t-butyl are all included isomers.
Also, more specifically, R3 is selected from a group consisting of hydrogen, alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, heterocycloalkyl, substituted heterocycloalkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl and silyl. Specific examples of R3 are methyl, ethyl, propyl, butyl, cyclopentyl, cylcohexyl, cyclooctyl, phenyl, naphthyl, benzyl, trimethylsilyl, and the like.
In other embodiments, when X is oxygen or sulfur and a is 1, R3 is selected from the group consisting of alkyl, substituted alkyl, heterocycloalkyl, substituted heterocycloalkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl or silyl. In one embodiment, R3 may be a substituted phenyl having from 1-5 substituents on the phenyl ring, with each of the substituents independently selected from the group consisting of alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, heteroalkyl, heterocycloalkyl, substituted heterocycloalkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, alkoxy, aryloxy, silyl, boryl, phosphino, amino, thio, seleno, and combinations thereof. More specifically, there are typically 1, 2 or 3 substituents on the substituted phenyl and the substituents are selected from the group consisting of chloro, fluoro, iodo, bromo, methyl, ethyl, propyl, butyl, cyclopentyl, cylcohexyl, cyclooctyl, phenyl, naphthyl, benzyl, trimethylsilyl and isomers thereof, where applicable.
Each of Q1 and Q2 is independently selected from the group consisting of hydrogen, alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, heterocycloalkyl, substituted heterocycloalkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, boryl, silyl, amino, phosphino, alkoxy, aryloxy, halogens, and combinations thereof. Specific examples of each of Q1 and Q2 are methyl, ethyl, propyl, butyl, phenyl, t-butyl, cyclohexyl, benzyl, acetyl, benzoyl, propionyl, pyridyl, morpholinyl, dimethylboryl, dibutylboryl, methylphenylboryl, diphenylboryl, trimethylsilyl, triphenylsilyl, dimethylphenylsilyl, dimethyl-t-butylsilyl, dimethylamino, diethylamino, methylphenylamino, benzylmethylamino, diphenylphosphino, dimethylphosphino, methylphenylphosphino, methoxy, phenoxy, benzyloxy, tetrahydropyranyl, chloro and bromo. Optionally, Q1 and Q2 are joined together in a ring structure. In those embodiments where Q1 and Q2 are joined together in a ring, the ring (including Q1, Q2 and the two carbon atoms in the backbone of the ligand) has from 4 to 15 non-hydrogen atoms in the backbone of the ring. Specific examples of ring are cyclohexene, cyclopentene, cyclobutene, cyclooctene, cyclopentadiene, naphthalene, anthracene, acridine, dihydrofuran, benzene, pyridine, oxazoline, furan, and thiophene. One form of this option is preferred, such that the ligands of this invention may be characterized by the general formula: 
wherein R1, R2, R3, X and a each have the definition given above. In addition, R4 is selected from the group consisting of electron withdrawing and electron donating groups and b is 0, 1, 2, 3 or 4. More specifically, of R4 may be chosen from the group consisting of alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, heterocycloalkyl, substituted heterocycloalkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, silyl, amino, alkoxy, aryloxy, phosphino, boryl, transition metals, halogens and combinations thereof. Specific examples of R4 include methyl, ethyl, propyl, butyl, pentyl, hexyl, phenyl, cyano, acetyl, benzoyl, nitro, dimethylamino, diethylamino, methylphenylamino, benzylmethylamino, trimethylsilyl, dimethylboryl, diphenylboryl, methylphenylboryl, dimethoxyboryl, chromium tricarbonyl, ruthenium tric cyclopentadienyl iron, and isomers thereof, where applicable. Optionally, two or more preferably four, R4 groups combine to form a fused ring structure with the aromatic group that forms a part of the ligand backbone. The additional fused ring may or may not contain a heteroatom. Examples of the aromatic group that is part of the backbone as combined with two or more R4 groups that have formed a fused ring are nathphalene, anthracene, quinoline, indole and the like.
Another embodiment is where the R1 group is a substituted or unsubstituted phenyl, such that the ligands of this invention may be characterized by the general formula: 
wherein R2, R3, R4, X, a and b each have the definition given above. In addition, R5 is selected from the group consisting of electron withdrawing and electron donating groups and c is 0, 1, 2, 3, 4 or 5. More specifically, of R5 may be chosen from the group consisting of alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, heterocycloalkyl, substituted heterocycloalkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, silyl, amino, alkoxy, aryloxy, phosphino, boryl, transition metals, halogens and combinations thereof. Specific examples of R5 include methyl, ethyl, propyl, butyl, pentyl, hexyl, phenyl, cyano, acetyl, benzoyl, nitro, dimethylamino, diethylamino, methylphenylamino, benzylmethylamino, trimethylsilyl, dimethylboryl, diphenylboryl, methylphenylboryl, dimethoxyboryl, chromium tricarbonyl, ruthenium tricarbonyl, cyclopentadienyl iron and isomers thereof, where applicable. Optionally, two or more R5 groups combine to form a fused ring structure with the aromatic group that forms a part of the ligand backbone. The additional fused ring may or may not contain a heteroatom. Examples of the aromatic group that is part of the backbone as combined with two or four R5 groups that have formed a fused ring are nathphalene, quinoline, indole, anthracene and the like, either substituted or not.
The preferred ligands are synthesized using an aryl amination reaction. The synthesis can be carried out in solution phase or solid phase (using organic or inorganic supports). For solid-phase synthesis, the ligands may be left on the support and used with metal added metal complexes as heterogeneous catalysts. Alternatively, the ligands can be cleaved either before or after reaction with a metal precursor and then used as a homogeneous catalyst. One the general route for synthesis of the ligands of this invention is shown below in scheme 1: 
where Xxe2x80x2 is a leaving group, such as a halogen, like Br, Cl, F or I or an aryl sulfonate, an alkyl sulfonate, triflate, nonaflate or another suitable leaving group. As shown in scheme 1, the synthesis employs an aryl amination reaction to attach the nitrogen group to the benzene ring at the appropriate location. The aryl amination reaction starts with a compound characterized by the general formula: 
wherein R3, R4, X, a and b are as defined above and Xxe2x80x2 is selected from the group consisting of chloro, bromo, iodo, triflate, nonaflate, alkyl sulfonates, aryl sulfonates and tosylate. Starting compounds of this type can be purchased from Aldrich Chemical Company or prepared using known techniques. See, e.g., Greene, Theodora W. and Wuts, Peter G. M., Protecting Groups in Organic Synthesis, 2nd Edition (John Wiley and Sons, New York, N.Y. 1991), herein incorporated by reference.
The aryl amination reaction uses an amine that can be characterized by the general formula HNR1R2, where R1 and R2 are as defined above. This aryl amination reaction is typically performed using a catalyst that comprises known or possibly new metal and ligand catalyst compositions. For example, the catalyst for the aryl amination reaction may be characterized by the general formula Mxe2x80x2/Lxe2x80x2, where Mxe2x80x2 is a complex that contains a metal selected from the group consisting of late transition metals, preferably a Group 10 metal such as Pd, Ni or Pt. Mxe2x80x2 is any homogeneous or heterogeneous metal precursor catalyst or catalyst. Lxe2x80x2 is a ligand that may be selected from the group consisting of phosphine or nitrogen ligands. Lxe2x80x2 may be monodentate, bidentate, tridentate, hemi-labile, unsubstituted or substituted, supported or unsupported, water-soluble or insoluble, soluble or insoluble in organic solvents including fluorinated solvents. The reaction can take place at known conditions, such as a temperature of from room temperature to about 150xc2x0 C. Aryl amination reactions are described in U.S. Pat. No. 5,576,460, herein incorporated by reference.
In some embodiments, it may be desirable to add a specific R2 group. In this case, the ligands can be made by starting with R2 as hydrogen and then adding a reactant to replace the hydrogen with the desired group in a reaction that may be characterized as shown below in Scheme 2: 
Once the desired ligand is formed, it may be combined with a metal atom, ion, compound or other metal precursor compound. In many applications, the ligands of this invention will be combined with such a metal compound or precursor and the product of such combination is not determined, if a product forms. For example, the ligand may be added to a reaction vessel at the same time as the metal or metal precursor compound along with the reactants. The metal precursor compounds may be characterized by the general formula M(L)n where M is a metal selected from the group consisting of Sc, Y and Groups 4, 5, 6, 7, 8, 9, 10, 11 and 12 of the Periodic Table of Elements. In more specific embodiments, M is selected from the group consisting of V, Ta, Ti, Zr, Zn, Cr, W, Mo, Ru, Os, Co, Ni, Pd, Fe and Mn. n is a number 0, 1, 2, 3, 4 or 5. L is a ligand chosen from the group consisting of halide, alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, heterocycloalkyl, substituted heterocycloalkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, alkoxy, aryloxy, hydroxy, boryl, silyl, hydrido, thio, seleno, phosphino, amino, and combinations thereof. When L is a charged ligand, L is selected from the group consisting of hydrogen, halogens, alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, heteroalkyl, heterocycloalkyl, substituted heterocycloalkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, alkoxy, aryloxy, silyl, boryl, phosphino, amino, thio, seleno, cyclopentadienyl, substituted cyclopentadienyl, imido, oxo and combinations thereof. When L is a neutral ligand, L is selected from the group consisting of carbon monoxide, isocyanide, nitrous oxide, PA3, NA3, OA2, SA2, SeA2, and combinations thereof, wherein each A is independently selected from a group consisting of alkyl, substituted alkyl, heteroalkyl, cycloalkyl, substituted cycloalkyl, heterocycloalkyl, substituted heterocycloalkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, alkoxy, aryloxy, silyl, and amino. Specific examples of suitable metal precursor compounds include Pd(dba)2 (dba=dibenzylideneacteone), Pd(OAc)2 (Ac=acetate) and the like. In this context, the ligand to metal precursor compound ratio is in the range of about 0.01:1 to about 100:1, more preferably in the range of about 0.5:1 to about 20:1.
In other applications, the ligand will be mixed with a suitable metal precursor compound prior to or simultaneous with allowing the mixture to be contacted to the reactants. When the ligand is mixed with the metal precursor compound, a metal-ligand complex may be formed, which may be a catalyst.
In one form, the metal-ligand complexes may be characterized by one of the following general formulas: 
wherein each R1, R2, R3, Q1, Q2 and X are as defined above; M is a transition metal selected from the group consisting of Sc, Y and Groups 4, 5, 6, 7, 8, 9, 10, 11 and 12 of the Periodic Table of Elements; L is independently each occurrence, a neutral and/or charged ligand; n is a number 0, 1, 2, 3, 4, or 5, depending on M and L; and a is 0, 1 or 2 depending on the element chosen for X and the type of bonding to M. For example, if X is oxygen or sulfur and the bonding is a dative bond (shown by the arrow), then a is 1. Similarly, if X is oxygen or sulfur and the bonding is a covalent bond, then a is 0. In other embodiments, X will be nitrogen that is datively bonded to M, meaning that a is 2. If X is nitrogen that is covalently bonded to M, then a is 1. In more specific embodiments, M is selected from the group consisting of V, Ta, Ti, Zr, Zn, Cr, W, Mo, Ru, Os, Co, Ni, Pd, Fe and Mn.
L is independently each occurrence, a neutral and/or charged ligand. Generally, L is a ligand chosen from the group consisting of halide, alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, heterocycloalkyl, substituted heterocycloalkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, alkoxy, aryloxy, hydroxy, boryl, silyl, hydrido, thio, seleno, phosphino, amino, cyclopentadienyl, substituted cyclopentadienyl, imido, oxo and combinations thereof. When L is a charged ligand, L is selected from the group consisting of hydrogen, halogens, alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, heteroalkyl, heterocycloalkyl, substituted heterocycloalkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, alkoxy, aryloxy, silyl, boryl, phosphino, amino, thio, seleno, and combinations thereof. When L is a neutral ligand, L is selected from the group consisting of arene, carbon monoxide, isocyanide, nitrous oxide, PA3, NA3, OA2, SA2, SeA2, and combinations thereof, wherein each A is independently selected from a group consisting of alkyl, substituted alkyl, heteroalkyl, cycloalkyl, substituted cycloalkyl, heterocycloalkyl, substituted heterocycloalkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, alkoxy, aryloxy, silyl, and amino.
n is the number 0, 1, 2, 3, 4, or 5. M can be neutral, cationic or anionic.
In yet another alternative form, the metal can bind only to the N atom. The various ligand embodiments can be rewritten in this form. For example, the metal complexes may be characterized by one of the general formulas: 
where in each R1, R3, R4, Q1, Q2, X, M, L, a, b and n are as defined above; and m is a number that is either 1, 2, 3 or 4.
When a preferred form of the ligand is employed, the metal complexes of this invention may be characterized by one of the following the general formulas: 
wherein each of R1, R2, R3, R4, M, L, X, a, b, m and n are as defined above.
When other preferred ligands are used, the metal complexes may be characterized by one of the following general formulas: 
wherein each of R2, R3, R4, R5, M, L, X, a, b, c, m and n are as defined above.
The ligands of this invention bind to a metal via the N and X atoms, optionally via only the N atom, as explained above. Coordination modes described above may or may not depend on the nature of ligands L on the metal M, and for a given ancillary ligand of this invention the coordination modes may switch from one to another at different stages of a catalytic cycle.
These transition metal-ligand complexes catalyze reactions involving activation of and formation of bonds between Hxe2x80x94Si, Hxe2x80x94H, Hxe2x80x94N, Hxe2x80x94O, Hxe2x80x94P, Hxe2x80x94S, Cxe2x80x94H, Cxe2x80x94C, Cxe2x95x90C, Cxe2x89xa1C, C-halogen, Cxe2x80x94N, Cxe2x80x94O, Cxe2x80x94S, Cxe2x80x94P, and Cxe2x80x94Si. Specifically, such reactions include carbonylation, hydroformylation, hydroxycarbonylation, hydrocarbonylation, hydroesterification, hydrogenation, hydrosilylation, hydroboration, hydroamination, epoxidation, aziridination, reductive amination, Cxe2x80x94H activation, insertion, Cxe2x80x94H activation-insertion, Cxe2x80x94H activation-substitution, C-halogen activation, C-halogen activation-substitution, C-halogen activation-insertion, alkene metathesis, alkyne metathesis, polymerization, alkene oligomerization, alkene polymerization, alkyne oligomerization, alkyne polymerization, co-polymerization, CO-alkene co-oligomerization, CO-alkene co-polymerization, CO-alkyne co-oligomerization and CO-alkyne co-polymerization. These reactions may occur at previously known conditions (or possibly novel conditions). Moreover, these reactions may be homogeneous or heterogeneous. In the case of heterogeneous reactions, the ligands may be supported, with or without the metal coordinated, on an organic or inorganic support. Suitable supports include silicas, aluminas, zeolites, polyethyleneglycols, polystyrenes, polyesters, polyamides, peptides and the like.
Polymerization or oligomerization catalysis with the compositions and metal complexes of this invention is a particularly effective process. In particular, the complexes and compositions of this invention are active catalysts also for the polymerization of olefins, diolefins or acetylenically unsaturated compounds, possibly in combination with an activator or activating technique. When an activator or activating technique is used, those of skill in the art may use alumoxanes, strong Lewis acids, compatible noninterfering activators and combinations of the foregoing. The foregoing activators have been taught for use with different metal complexes in the following references, which are hereby incorporated by reference in their entirety: U.S. Pat. Nos. 5,599,761, 5,616,664, 5,453,410, 5,153,157, 5,064,802, and EP-A-277,004. Preferred activators include methylalumoxane, trimethylaluminum, AgBF4, AgBPh4, AgBArxe2x80x24, NaBArxe2x80x24, H(OEt2)2BArxe2x80x24 and the like (where Arxe2x80x2 is a substituted aromatic, like perfluorophenyl or 3,5-(CF3)2(C6H3)). An example of a Lewis acid activator is B(C6F5)3.
Suitable activators for use herein include polymeric or oligomeric alumoxanes, especially methylalumoxane, triisobutyl aluminum modified methylalumoxane, or diisobutylalumoxane; strong Lewis acids (the term xe2x80x9cstrong Lewis acidxe2x80x9d as used herein is defined as trihydrocarbyl substituted Group 13 compounds, especially tri(hydrocarbyl)aluminum- or tri(hydrocarbyl)boron compounds and halogenated derivatives thereof, having from 1 to 10 carbons in each hydrocarbyl or halogenated hydrocarbyl group, more especially perfluorinated tri(aryl)boron compounds, and most especially tris(pentafluorophenyl)borane); amine, phosphine, aliphatic alcohol and mercaptan adducts of halogenated tri(C1-10 hydrocarbyl)boron compounds, especially such adducts of perfluorinated tri(aryl)boron compounds; nonpolymeric, ionic, compatible, noncoordinating, activating compounds (including the use of such compounds under oxidizing conditions); and combinations of the foregoing activators and techniques.
Combinations of strong Lewis acids, especially the combination of a trialkyl aluminum compound having from 1 to 4 carbons in each alkyl group and a halogenated tri(hydrocarbyl)boron compound having from 1 to 10 carbons in each hydrocarbyl group, especially tris(pentafluorophenyl)borane; further combinations of such strong Lewis acid mixtures with a polymeric or oligomeric alumoxane; and combinations of a single strong Lewis acid, especially tris(pentafluorophenyl)borane with a polymeric or oligomeric alumoxane are especially desirable activators.
Suitable compounds useful as a cocatalyst in one embodiment of the present invention comprise a cation which is a Bronsted acid capable of donating a proton, and an inert, compatible, noncoordinating, anion, Axe2x88x92. Preferred anions are those containing a single coordination complex comprising a charge-bearing metal or metalloid core which anion is capable of balancing the charge of the active catalyst species (the metal cation) which is formed when the two components are combined. Also, said anion should be sufficiently labile to be displaced by olefinic, diolefinic and acetylenically unsaturated compounds or other neutral Lewis bases such as ethers or nitrites. Suitable metals include, but are not limited to, aluminum, gold and platinum. Suitable metalloids include, but are not limited to, boron, phosphorus, and silicon. Compounds containing anions which comprise coordination complexes containing a single metal or metalloid atom are, of course, well known and many, particularly such compounds containing a single boron atom in the anion portion, are available commercially. Therefore, said single boron atom compounds are preferred.
Preferably such activators may be represented by the following general formula:
(L*xe2x80x94H)+d(Adxe2x88x92)
wherein: L* is a neutral Lewis base; (L*xe2x80x94H)+ is a Bronsted acid; Adxe2x88x92 is a noncoordinating, compatible anion having a charge of dxe2x88x92, and d is an integer from 1 to 3. More preferably Adxe2x88x92 corresponds to the formula: (Mk+Qn)dxe2x88x92, wherein: k is an integer from 1 to 3; n is an integer from 2 to 6; nxe2x88x92k=d; Mxe2x80x2 is an element selected from Group 13 of the Periodic Table of the Elements; and Q independently each occurrence is selected from hydride, dialkylamido, halide, alkoxide, aryloxide, hydrocarbyl, and halosubstituted-hydrocarbyl radicals, said Q having up to 20 carbons with the proviso that in not more than one occurrence is Q halide.
In a more preferred embodiment, d is one, i.e. the counter ion has a single negative charge and corresponds to the formula Axe2x88x92. Activators comprising boron which are particularly useful in the preparation of catalysts of this invention may be represented by the following general formula: (L*xe2x80x94H)+(BQxe2x80x24)xe2x88x92 wherein: L* is as previously defined; B is boron in an oxidation state of 3; and Qxe2x80x2 is a fluorinated C1-20 hydrocarbyl group. Most preferably, Qxe2x80x2 is in each occurrence a fluorinated aryl group, especially a pentafluorophenyl group.
Illustrative, but not limiting examples of boron compounds which may be used as an activating cocatalyst in the preparation of the improved catalysts of this invention are tri-substituted ammonium salts such as:
trimethylammonium tetraphenylborate,
triethylammonium tetraphenylborate,
tripropylammonium tetraphenylborate,
tri(n-butyl)ammonium tetraphenylborate,
tri(t-butyl)ammonium tetraphenylborate,
N,N-dimethylanilinium tetraphenylborate,
N,N-diethylanilinium tetraphenylborate,
N,N-dimethyl-(2,4,6-trimethylanilinium)tetraphenylborate,
trimethylammonium tetrakis(pentafluorophenyl)borate,
triethylammonium tetrakis(pentafluorophenyl)borate,
tripropylammonium tetrakis(pentafluorophenyl)borate,
tri(n-butyl)ammonium tetrakis(pentafluorophenyl)borate,
tri(sec-butyl)ammonium tetrakis(pentafluorophenyl)borate,
N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate,
N,N-diethylanilinium tetrakis(pentafluorophenyl)borate,
N,N-dimethyl-(2,4,6-trimethylanilinium)tetrakis(pentafluorophenyl)borate, trimethylammonium
tetrakis-(2,3,4,6-tetrafluorophenylborate,
triethylammonium tetrakis-(2,3,4,6-tetrafluorophenyl)borate,
tripropylammonium tetrakis-(2,3,4,6-tetrafluorophenyl)borate,
tri(n-butyl)ammonium tetrakis-(2,3,4,6-tetrafluoro-phenyl)borate,
dimethyl(t-butyl)ammonium tetrakis-(2,3,4,6-tetrafluorophenyl)borate,
N,N-dimethylanilinium tetrakis-(2,3,4,6-tetrafluorophenyl)borate,
N,N-diethylanilinium tetrakis-(2,3,4,6-tetrafluoro-phenyl)borate, and
N,N-dimethyl-(2,4,6-trimethylanilinium)tetrakis-(2,3,4,6-tetrafluorophenyl)borate;
dialkyl ammonium salts such as: di-(i-propyl)ammonium tetrakis(pentafluorophenyl)borate, and dicyclohexylammonium tetrakis(pentafluorophenyl)borate, and
tri-substituted phosphonium salts such as: triphenylphosphonium tetrakis(pentafluorophenyl)borate, tri(o-tolyl)phosphonium tetrakis(pentafluorophenyl)borate, and tri(2,6-dimethylphenyl)phosphonium tetrakis(pentafluorophenyl)borate.
Preferred [L*xe2x80x94H]+ cations are N,N-dimethyl-anilinium and tributylammonium.
Another suitable ion forming, activating cocatalyst comprises a salt of a cationic oxidizing agent and a noncoordinating, compatible anion represented by the formula: (OXe+)d(Adxe2x88x92)e,
wherein:
Oxe+ is a cationic oxidizing agent having a charge of e+; e is an integer from 1 to 3; and Axe2x88x92, and d are as previously defined.
Examples of cationic oxidizing agents include: ferrocenium, hydrocarbyl-substituted ferrocenium, Ag+, or pb+2. Preferred embodiments of Adxe2x88x92 are those anions previously defined with respect to the Bronsted acid containing activators, especially tetrakis(pentafluorophenyl)borate.
Another suitable ion forming, activator comprises a compound which is a salt of a carbenium ion and a noncoordinating, compatible anion represented by the formula: (C)+Axe2x88x92, wherein: (C)+ is a C1-20 carbenium ion; and Axe2x88x92 is as previously defined. A preferred carbenium ion is the trityl cation, i.e. triphenylcarbenium.
The foregoing activating technique and ion forming activators are also preferably used in combination with a tri(hydrocarbyl)aluminum compound having from 1 to 4 carbons in each hydrocarbyl group, an oligomeric or polymeric alumoxane compound, or a mixture of a tri(hydrocarbyl)aluminum compound having from 1 to 4 carbons in each hydrocarbyl group and a polymeric or oligomeric alumoxane.
Ratios of neutral complex to activator are on the order of 1 to 1000 to 1000 to 1. A scavenger can also be used with this invention. Scavengers useful herein include metal complexes, alumoxanes, aluminum alkyls, Lewis acids and the like. Other additives that are standard for polymerization reactions can be used.
The catalysts herein may be used to polymerize ethylenically or acetylenically unsaturated monomers having from 2 to 20 carbon atoms either alone or in combination. Monomers include C2 to C20 xcex1-olefins such as ethylene, propylene, 1-butene, 1-hexene, 1-octene, 4-methyl-1-pentene, styrene and mixtures thereof.
The compounds and catalysts of this invention usefully polymerize functionalized monomers, such as acetates and acrylates. Novel polymers, copolymers or interpolymers may be formed having unique physical and/or melt flow properties. Such novel polymers can be employed alone or with other polymers in a blend to form products that may be molded, cast, extruded or spun. End uses for the polymers made with the catalysts of this invention include films for packaging, trash bags, foams, coatings, insulating devices and household items. Also, such functionalized polymers are useful as solid supports for organometallic or chemical synthesis processes.
Polymerization can be carried out in the Ziegler-Natta or Karninsky-Sinn methodology, including temperatures of from 0xc2x0 C. to 400xc2x0 C. and pressures from atmospheric to 3000 atmospheres. In a preferred embodiment the process is a continuous process at a temperature of between xe2x88x92100xc2x0 C. and 500xc2x0 C. Suspension, solution, slurry, gas phase or high-pressure polymerization processes nay be employed with the catalysts and compounds of this invention. Such processes can be run in a batch or continuous mode. Examples of such processes are well known in the art. A support for the catalyst may be employed, which may be alumina, silica or a polymers support. Methods for the preparation of supported catalysts are known in the art. Slurry, suspension, solution and high-pressure processes use a suitable solvent as known to those skilled in the art.
The ligands, metal-ligand complexes and compositions of this invention can be prepared and tested for catalytic activity in one or more of the above reactions in a combinatorial fashion. Combinatorial chemistry generally involves the parallel or rapid serial synthesis and/or screening or characterization of compounds and compositions of matter. U.S. Pat. No. 5,776,359 generally discloses combinatorial methods and WO 98/03521 discloses combinatorial methods for organometallic chemistry, both of which are incorporated herein by reference. In this regard, the ligands, complexes or compositions may be prepared and/or tested in rapid serial and/or parallel fashion, e.g., in an array format. When prepared in an array format, for example, the ligands may be take the form of an array comprising a plurality of compounds wherein each compound can be characterized by either of the general formulas: 
wherein each R1, R2, R3, R4, R5, Q1, Q2, X, a, b and c is as defined above.
In such a combinatorial array, typically each of the plurality of compounds has a different composition and each compound is at a selected region on a substrate such that each compound is isolated from the other compounds. This isolation can take many forms, typically depending on the substrate used. If a flat substrate is used, there may simply be sufficient space between regions so that there cannot be interdiffusion between compounds. As another example, the substrate can be a microtiter or similar plate having wells so that each compound is in a region separated from other compounds in other regions by a physical barrier.
The array typically comprises at least 10 ligands, compounds, complexes or compositions each having a different chemical formula, meaning that there must be at least one different atom or bond differentiating the plurality in the array. In other embodiments, there are at least 25 compounds, complexes or compositions on or in the substrate each having a different chemical formula. In still other embodiments, there are at least 50 or 96 or 124 ligands, compounds, complexes or compositions on or in the substrate each having a different chemical formula. Because of the manner of forming combinatorial arrays, it may be that each compound, complex or composition is not pure. Typically, each compound in the plurality of compounds is at least 50% pure within its region. In other embodiments, each element of the array comprises the composition of matter described above, comprising the ligand and a metal precursor. The same array discussion above applies to arrays of this type. In still other embodiments, each element of the array is a metal-ligand complex defined above, including complexes V, VI, VII, VIII, IX, X, XI, XII, XIII, XIV, XV and XVI. The same array discussion above applies to arrays of this type.
The catalytic performance (activity and/or selectivity) of the ligands of this invention in combination with a suitable metal precursor, compositions of this invention or metal-ligand complexes of this invention can be tested in a combinatorial or high throughput fashion. For any of the listed transformations, thin layer chromatography (TLC) in combination with imaging technology may be employed. TLC is well known in the art, see for example Vol. 1, Thin-Layer Chromatography, Reagents and Detection Methods, Jork et al. (VCH Publishers, New York, N.Y. 1990), incorporated herein by reference. Polymerizations or oligomerizations can also be performed in a combinatorial fashion, see, e.g., commonly owned provisional U.S. Patent Application No. 60/096,603, filed Aug. 13, 1998, herein incorporated by reference. High throughput screening can also be performed optically and in parallel, for example, as disclosed in commonly owned U.S. patent applications Ser. No. 09/067,448, filed Apr. 2, 1998, Ser. No. 08/947,085, filed Oct. 8, 1997, now U.S. Pat. No. 6,034,775, and Ser. No. 08/946,135, filed Oct. 7, 1997, now U.S. Pat No. 6,541,271, each of which is incorporated by reference.